Start proper connection handshake

2 files changed, 54 insertions, 4 deletions

diff --git a/src/main.zig b/src/main.zig
index f43f2bd..3959f08 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -30,7 +30,9 @@ pub fn main() !void {
     try Saprus.init();
     defer Saprus.deinit();
 
-    try Saprus.sendInitialConnection(if (message.items.len > 0) message.items else "Hello darkness my old friend", 6868, gpa);
+    // _ = try Saprus.sendInitialConnection(if (message.items.len > 0) message.items else "Hello darkness my old friend", 6868, gpa);
+
+    try Saprus.connect(if (message.items.len > 0) message.items else "Hello darkness my old friend", gpa);
 
     // try Saprus.sendRelay(if (message.items.len > 0) message.items else "Hello darkness my old friend", gpa);
 }
diff --git a/src/saprus.zig b/src/saprus.zig
index fce3dc7..b29a381 100644
--- a/src/saprus.zig
+++ b/src/saprus.zig
@@ -1,4 +1,12 @@
+var rand: ?Random = null;
+
 pub fn init() !void {
+    var prng = Random.DefaultPrng.init(blk: {
+        var seed: u64 = undefined;
+        try posix.getrandom(mem.asBytes(&seed));
+        break :blk seed;
+    });
+    rand = prng.random();
     try network.init();
 }
 
@@ -42,12 +50,17 @@ pub fn sendRelay(payload: []const u8, allocator: Allocator) !void {
     try broadcastSaprusMessage(msg, allocator);
 }
 
-pub fn sendInitialConnection(payload: []const u8, initial_port: u16, allocator: Allocator) !void {
+pub fn sendInitialConnection(payload: []const u8, initial_port: u16, allocator: Allocator) !SaprusMessage {
+    var dest_port: u16 = 0;
+    if (rand) |r| {
+        dest_port = r.intRangeAtMost(u16, 1024, 65000);
+    } else unreachable;
+
     const msg = SaprusMessage{
         .connection = .{
             .header = .{
                 .src_port = initial_port,
-                .dest_port = 6868,
+                .dest_port = dest_port,
                 .seq_num = 1,
                 .msg_id = 2,
                 .reserved = 5,
@@ -57,10 +70,45 @@ pub fn sendInitialConnection(payload: []const u8, initial_port: u16, allocator:
     };
 
     try broadcastSaprusMessage(msg, allocator);
+
+    return msg;
+}
+
+fn awaitSentinelConnectionResponse(res: *?SaprusMessage) !void {
+    res.* = SaprusMessage{
+        .relay = .{
+            .header = .{
+                .dest = .{ 255, 255, 255, 255 },
+            },
+            .payload = "",
+        },
+    };
+    std.Thread.sleep(3 * 1000 * 1000 * 1000);
+}
+
+pub fn connect(payload: []const u8, allocator: Allocator) !void {
+    var initial_port: u16 = 0;
+    if (rand) |r| {
+        initial_port = r.intRangeAtMost(u16, 1024, 65000);
+    } else unreachable;
+
+    var initial_conn_res: ?SaprusMessage = null;
+    const response_thread = try std.Thread.spawn(.{}, awaitSentinelConnectionResponse, .{&initial_conn_res});
+
+    const msg = try sendInitialConnection(payload, initial_port, allocator);
+    std.debug.print("msg: {any}\n", .{msg});
+
+    response_thread.join();
+    std.debug.print("initial_conn_res: {any}\n", .{initial_conn_res});
 }
 
 const SaprusMessage = @import("./saprus_message.zig").SaprusMessage;
+
 const std = @import("std");
+const Random = std.Random;
+const posix = std.posix;
+const mem = std.mem;
+
 const network = @import("network");
 
-const Allocator = std.mem.Allocator;
+const Allocator = mem.Allocator;